One aspect relates to an electrical bushing for use in a housing of an implantable medical device. Moreover, one aspect relates to a method for the manufacture of an electrical bushing for an implantable medical device.
The post-published document, DE 10 2009 035 972, discloses an electrical bushing for an implantable medical device having the features of the preamble of claim 1. Moreover, a use of at least one cermet-including conducting element in an electrical bushing for an implantable medical device and a method for the manufacture of an electrical bushing for an implantable medical device are disclosed.
A multitude of electrical bushings for various applications are known, examples including: U.S. Pat. Nos. 4,678,868, 7,564,674 B2, US 2008/0119906 A1, U.S. Pat. Nos. 7,145,076 B2, 7,561,917, US 2007/0183118 A1, U.S. Pat. Nos. 7,260,434B1, 7,761,165, 7,742,817 B2, 7,736,191 B1, US 2006/0259093 A1, U.S. Pat. No. 7,274,963 B2, US 2004116976 A1, U.S. Pat. No. 7,794,256, US 2010/0023086 A1, U.S. Pat. Nos. 7,502,217 B2, 7,706,124 B2, 6,999,818 B2, EP 1754511 A2, U.S. Pat. No. 7,035,076, EP 1685874 A1, WO 03/073450 A1, U.S. Pat. Nos. 7,136,273, 7,765,005, WO 2008/103166 A1, US 2008/0269831, U.S. Pat. No. 7,174,219 B2, WO 2004/110555 A1, U.S. Pat. No. 7,720,538 B2, WO 2010/091435, US 2010/0258342 A1, US 2001/0013756 A1, U.S. Pat. No. 4,315,054, and EP 0877400.
DE 697 297 19 T2 describes an electrical bushing for an active implantable medical device—also called implantable device or therapeutic device. Electrical bushings of this type serve to establish an electrical connection between a hermetically sealed interior and an exterior of the therapeutic device. Known implantable therapeutic devices are cardiac pacemakers or defibrillators, which usually include a hermetically sealed metal housing which is provided with a connection body, also called header, on one of its sides. Said connection body includes a hollow space having at least one connection socket for connecting electrode leads. In this context, the connection socket includes electrical contacts in order to electrically connect the electrode leads to the control electronics on the interior of the housing of the implantable therapeutic device. Hermetic sealing with respect to a surrounding is an essential prerequisite of an electrical bushing of this type. Therefore, lead wires that are introduced into an electrically insulating base body—also called signal-transmission elements—through which the electrical signals are propagated, must be introduced into the base body such as to be free of gaps. In this context, it has proven to be challenging that the lead wires generally are made of a metal and are introduced into a ceramic base body. In order to ensure a durable connection between the two elements, the internal surface of a through-opening—also called openings—in the base body is metallized for attachment of the lead wires by soldering. However, the metallization in the through-opening has proven to be difficult to apply. Only expensive procedures ensure homogeneous metallization of the internal surface of the bore hole and thus a hermetically sealed connection of the lead wires to the base body by soldering. The soldering process itself requires additional components, such as solder rings. Moreover, the process of connecting the lead wires to the previously metallized insulators utilizing the solder rings is a process that is laborious and difficult to automate.
Printed publication U.S. Pat. No. 7,502,217 B2 describes a bushing for implantable devices, in which connection pins made of metal extend through an opening of an insulator. Aside from a filter capacitor, the bushing includes a coil as a separate component that is provided as a toroidal coil made of wire. A ring-shaped groove is provided in the bushing to accommodate the toroidal coil, which is embedded therein. The toroidal coil is connected to the filter capacitor and other wire connections of the bushing through solder connections. As a result, there are multiple connections concerning a multitude of components which have to be established through soldering. This not only renders the manufacturing method highly complex, but also makes the manufacture highly error-prone since the soldering steps concern different components, which each must be soldered in a certain way only. Due to the proximity of the various components to be soldered with respect to each other, especially in miniaturized versions, there is a risk that undesired solder connections may arise, even more so since previously established solder connections are partially melted again in each step of soldering. Moreover, an additional manufacturing step of introducing the groove in the bushing is required. And lastly, the bushing body needs to be provided in the form of multiple parts in order to be able to take up the toroidal coil, whereby the multiple parts need to be connected to each other in an additional step.
For these and other reasons there is a need for the present invention.